Sewage pumping system with electric motor operated discharge valve



Dec. 12, 1961 L. KUSNER 3, ,5

SEWAGE PUMPING SYSTEM WITH ELECTRIC MOTOR OPERATED DISCHARGE VALVE Filed Feb. 21, 1958 2 Sheets-Sheet 1 Fig.

To A. G. Source 24 INVENTOR. LOUIS KUSNER ATTORNEY Dec. 12, 1961 KUSNER SEWAGE PUMPING SY 3,012,510 STEM WITH ELECTRIC MOTOR OPERATED DISCHARGE VALVE 2 Sheets-Sheet 2 Filed Feb. 21, 1958 INVENTOR. LOUIS KUSNER 4 35cm m 0 4 E.

ATTORNEY power source.

United States Patent Ofiice 3,012,510 SEWAGE PUMPlN G SYSTEM WITH ELECTRIC MOTOR OPERATED DISCHARGE VALVE Louis Kusner, 2101 Walnut St., Philadelphia 3, Pa. Filed Feb. 21, 1958, Ser. No. 716,597 4 Claims. (Cl. 103-40) This invention relates to a sewage, water, oil or chemical pumping system, the primary ob ect of which is to provide an economical, efiicient, safe and automatic means for closing the discharge valve in the event of failure or interruption of power to the pump motor.

When power failure or interruption occurs, it becomes necessary to shut the valve at the discharge end of the pump to minimize reverse flow of liquid through the pump to the suction well. In large pumping installations, such as municipally operated sewage and water works, the reverse flow may be sufiicient to unscrew the pump impeller and to set up vibrations which will damage the pump motor and associated piping.

Heretofore a hydraulic power accumulator was employed automatically to close the discharge valve upon power failure or interruption. Hydraulic pressure was applied to a double acting piston whose rod was operatively connected to the rotary or gate discharge valve closing mechanism. The power accumulator has several disadvantages. First, the power accumulator system occupies a large volume so that its use is prohibited where spatial considerations apply, as in underground pumping systems. Second, it is expensive to install and maintain and depends greatly upon the reliability of the hydraulic Third, when the hydraulic system goes into operation at pump power failure, the accumulated pressure becomes depleted as the discharge valve is closed. Thus should pump power again fail before hydraulic power is accumulated, the accumulator system could not function to close the valve. Furthermore, valve closure is relatively slow because the accumulator steadily loses hydraulic power as the valve is actuated.

It is an important object of this invention to provide a valve closing mechanism which overcomes the disadvantages of the hydraulic pressure accumulator system. This is accomplished by operatively connecting the discharge valve to a direct current source via controls which automatically go into operation when the alternating current power to the pump motor fails or is interrupted.

Another object of the invention is to provide a valve control system of the character described whereby complete and uninterrupted closure of the discharge valve by the direct current motor is effected even though the alternating current to the pumping system may return to the system prior to complete valve closure.

These and other objects of the invention will become more apparent as the following description proceeds in conjunction with the accompanying drawing, wherein:

FIG. 1 is a diagrammatic view of the pumping and valve closing mechanism embodying the present invention; and

FIG. 2 is a wiring diagram of the mechanism.

Specific reference is now made to the drawing wherein like reference chmacters are used for like parts throughout.

The overall pumping and discharge valve control system is shown in FIG. 1 and consists of an intake pipe 10 connected to a pump 12, preferably centrifugal or mixed flow, a discharge pipe 14 connected to the pump and a discharge valve 16, preferably rotary or gate, interposed in the discharge pipe. motor 18 which is operatively connected to a source of alternating current.

The valve 16 is operatively connected to the shaft of The pump is driven by a 3,012,510 Patented Dec. 12, 1961 A.C. source asthe pump motor 18. The A.C. motor 20, when actuated after the pump motor 18 has acquired the desired speed, acts to open the valve 16.

A DC. motor 22 is coupled to the shaft of the A.C. motor 20, the DC. motor deriving its power from a direct current source such as a storage battery 24.

The pump motor 18, valve opening A.C. motor 20, valve closing DC motor 22, A.C. source and DC. source 24 are operatively interrelated by controls 26 so that upon failure or interruption of the A.C. source, the DC. motor 22 will automatically take over and close the valve 16, the Valve closure operation going to completion even if the A.C. power should return prior thereto, as will appear in greater detail hereafter in connection with the description of FIG. 2.

A switch 28 is interposed in a control circuit 30 which is connected to a magnet coil 32 that is operatively connected to a circuit breaker 34 in the lines 36 leading from the pump motor 18 to the A.C. source. The control circuit is carried through a conventional gear operated limit switch 38 which is closed when the valve 16 is closed, thus preventing energizing of the pump motor 18 until the valve closing is complete. The motor. of course, is started by actuation of the switch 28.

After the pump motor has attained the desired speed, it is necessary to open the discharge valve 16. The valve 16 is connected by appropriate gearing or other mechanical elements to the valve motor 20 which is operatively connected to the A.C. source by conductive wires 40 carrying a circuit breaker 42. The circuit includes a switch 44, a magnet coil 46 and a gear operated limit switch 48 in series which is normally closed. Actuation of the switch 44 energizes the magnet coil 46 which is connected to the reversing type magnetic motor starter of the valve motor 20 thereby causing the motor to move the valve 16 in the opening direction. Completion of valve opening opens limit switch 48 thereby deenergizing magnet coil 46 and stopping the valve motor 20. An open auxiliary switch 49 may be included in this circuit which is actuated by the closing of the pump motor circuit breaker 34 to prevent opening of the discharge an A.C. motor 20' which derives its power from the same valve 16 until the pump motor is energized.

The valve control circuit also includes another switch 50 which is operatively connected in series to another magnet coil 52 associated with the starter of motor 20, the circuit being carried through a normally closed gear operated limit switch 54 which is in turn operatively con nected to the circuit breaker 34 via a normally closed limit switch 56 connected to magnet coil 32. Thus when switch 50 is actuated, the valve motor 20 operates in a reverse direction to close the valve and when the valve operation is completed, the limit switch 54 opens deenergizing coil 52 and stopping the valve motor 20. At the same time, limit switch 56 opens, deenergizing coil 32 and stopping the pump motor 18.

The aforementioned control system prevents deenergizing of the pump motor 18 before the discharge valve 16 is completely closed. If the pump stopped before valve closure was completed, the head in the discharge pipe 14 would cause a back flow of fluid into the pump and suction well.

In the event of power failure or interruption in the A.C. source, magnet coil 32 becomes deenergized, circuit breaker 34 opens and contact 56 in the circuit 30 closes, but no power is available to close the discharge valve 16 by its A.C. motor 20 which is necessary to prevent liquid flow reversal and reverse rotation of the pump 12 and its motor 18.

To provide a means for automatically closing the valve when A.C. power fails or is interrupted, a transformer 58 is provided whose primary is operatively connected to the A.C. power source, the secondary winding of which is connected to the magnet coil 60 of an undervoltage relay whose contacts 62 are inserted in a control circuit 64 which includes the direct current source or storage battery 24, said contacts 62 remaining open in the pres ence of AC. voltage and closing in the absence of A.C. voltage. The motor 22 is coupled to the shaft of the valve A.C. motor 20 and is operatively connected to the DC. source 24 viacontacts 66 of the motors nonreversing starter. Control circuit 64 includes a magnet coil 68 which is operatively connected to contacts 66 and a normally closed limit switch 70. Thus wl1en,A.C. power fails or is interrupted, the contacts 62 of the undervoltage relay close. This energizes magnet coil 68 closing the contacts 66 of the starter of the motor 22 causing the latter to drive the valve 16 towards the closed position. When the valve is completely closed, limit switch 70 opens, de-energizing magnet coil 68 and stopping the DC.

- motor 22.

Since undervoltage relay60 is of the time-delay type arranged so that the contacts 62 do not reopen until the time required for closing valve 16 by the DC. 'motor 22 transpires, return of A.C. power prior to complete closing "of the valve will not reopen contacts 62 and complete closing of the valve by the DC. motor will be permitted.

While a preferred embodiment of the invention has been shown and described herein, a skilled artisan may make minor variations without departing from the spirit of the invention and the scope of the appended claims. Thus, for example, instead of employing a separate DC. motor, the motor 20 for operating the discharge valve 16 may be of the A.C.-DC. type (universal). The principles of the invention are also applicable to the case where the pump motor 18 and valve operating motor 20 are energized from a common direct current source and when said direct current source fails or is interrupted, the direct current motor 22, deriving its energy from a separate source, such as a storage battery 24, automatically acts to close the valve.

I claim: a

1. In a pumping system, a pump motor, an A.C.power source, a source of DC. power, a control circuit elecing said pump motor energized wh-ilesaid valve is open,

and means opcratively connected to said DC. motor for selectively maintaining said DC. motor de-energized when said A.C. motor is energized by said A.C; power source and maintaining said DC. motor energized when. said A.C. motor is 'de-energized.

2. The pumping system of claim 1 wherein said last mentioned means comprises a transformer having one winding operatively connected to said A.C. powersource and the other winding operatively connected to a solenoid, and switch means interposed in the circuit between said DC. motor and said source of DC. power, said switch means being controlled by said solenoid, said switch means being constructed and arranged to be maintained open by said solenoid when said solenoid is energized by said A.C. power source and to be closed when said solenoid is de-encrgized.

3. The pumping system of claim 2 wherein said switch means is constructed and arranged to be maintained closed for a predetermined time interval after re-energization of said solenoid.

4. The pumping system of claim 1 wherein said A.C. motor is reversible and is in circuit with saidA.C. power source through a pai-r'ofopposed relay means, said relay trically connecting said pump motor to said.A.C. power 7 valve, said A.C. motor being in circuit with said A.C. 'power source for energization thereby and said D.C. mo-

tor being in circuit with said source of DC. power for energization thereby, a limit switch assembly operatively means being selectively actuatable to connect said A.C. motor to opposite sides of said AC; power source to selectively open and close said valve. 7

References Cited in the file of this patent UNITED STATES PATENTS 2,847,179 Payzer Aug. 12, 1958 

